Rough Endoplasmic Reticulum
The rough endoplasmic reticulum (RER) is an organelle covered in ribosomes (hence the rough texture) present in eukaryotic cells. The RER works with its membrane-bound ribosomes to translate polypeptides and amino acids into proteins for the plasma membrane, Golgi apparatus, secretory vesicles, lysosomes, endosomes, and the ER itself. In plant cells, the RER also makes proteins for the vacuoles. Inside the RER, the proteins are folded to produce the structures that are used as recognition and linking sites. Any that are formed or folded incorrectly are rejected and eventually recycled. These proteins are then transported to the Golgi apparatus for completion in vesicles, or small droplets surrounded by a membrane.